Behavioral Couples Therapy (BCT) is associated with positive outcomes for alcoholic couples, both in terms of reduced alcohol use and increased relationship functioning. In a recent investigation, we showed, for the first time, that married or cohabiting men who primarily abused drugs other than alcohol randomly assigned to participate in BCT (N = 40) reported fewer days of drug use, longer periods of abstinence, fewer drug-related arrests, and fewer drug-related hospitalizations through the 12-month posttreatment follow-up period than husbands randomly assigned to receive individual-based treatment (IBT) only (N = 40). Furthermore, couples who received BCT reported better relationship outcomes, in terms of relationship satisfaction and less time separated, than couples whose husbands received IBT. A cost outcomes analysis revealed BCT was more cost-beneficial and cost-effective than IBT. However, five factors limit the generalizability of these findings: (a) only substance-abusing men with nonsubstance-abusing partners were recruited for the study; (b) it is unclear if the effects observed were due to the BCT interventions or simply the result of attention provided to the spouses; (c) BCT and IBT were provided in the context of a very intensive outpatient program (56 sessions over a 6-month period); (d) a relatively high proportion of participants were mandated by the criminal justice system (i.e., over 80 percent) to engage in and complete treatment; and (e) the participants used in the study were fairly heterogeneous in terms of their substance use backgrounds, which may have added unnecessary sampling variance and thereby reducing statisical power for analyses. The PRIMARY OBJECTIVE of the proposed study is to conduct a randomized clinical trial with 180 married or cohabiting drug- abusing patients and their nonsubstance-abusing partners to examine the comparative clinical efficacy, in terms 1-year posttreatment of drug-using behavior, relationship adjustment (i.e., spousal violence, relationship satisfaction, and stability), and other psychosocial outcomes, of BCT versus (a) and equally intensive IBT for drug-abusing patients only, (b) an equally intensive Psychoeducational Attention Control Condition (PACT) for drug-abusing patients and their partners. The SECONDARY OBJECTIVE is to determine if BCT is more cost-beneficial and cost-effective than IBT or PACT. This Stage II study extends our previous work by (a) including substance-abusing women and their nonsubstance-abusing partners, (b) adding an attention control condition, (c) delivering all interventions in the context of a less intensive overall treatment regimen, and (d) recruiting more homogeneous participants of which a much smaller proportion are mandated to treatment by the legal system.